Apparatus for treating fatty material



May 23, 1944. H. o. RENNER 2,349,373

' APPARATUS Foix TREATINGFATTY MATERIALS v Original Filed Jan. 10, 1940 4 SheefsSheet 1 May 23, 1944.

H. o. RENNER APP'ARATUS FOR TREATING FATTY MATERIALS n original Filed Jan. 1o, 1940 I I -llu 4 Sheets-Sheet 2 May 23,v 1944.

APPARATUS FOR TREATING' FATTY MATERIALS 4' Sheets-She'et 3' H. o. RENNER- 2,349,378

0rgna .1 Filed Jan. 10, 1940 Mai 2,3 1944. H. QRENNER A 2,349,378

APPARATUS FQR TREATING PATTY; MATERIALS original Filed Jan. 1o. 1940 4 Isneeis-s11eei 4 Herbert Otto er, illes Haines,

by mensslents, to I. E.. Short l l, @ampliar @hiesigen` mi., n aeration or ldlii alla, (im. Zbl- 93) This invention relates toprovements in' apparatus for ne. f' a treating reagent with a liquid to beV treated and especially for treating tion relates to apparatus for the treatment oi fatty acid compositions such as vegetable and aal glyceridesof fatty acids and the fatty acids themselves to prevent the development oi undesirable odors or iiavors therein. This application is a continuation ci application vSerial No.'

.lili-ldt, filed qlanuary l0, 1940, from which it has been divided.

in the treatment of edible fats and oils by various processes applied-prior to their use in loods or in other coodities where avor or odor are importantcbnsideratlons, products ob-v tained may at times contain certain constituents that have undesirable odors and avors or constituents from which such odors or navors are developed evenv after the use of such products in,

tor instance, foods such as baked or other goods.v

lll'he undesirable odors and flavors may be asvarious substances initially in the fats and oils or are prepared from lees such as soybeans conv -iatty material inclus edible oils. and iats'or es thereof. More particularly, the inven extent oi oxidation desired. The enzyme extracts .l 1; peromdizing ees. ll'he peroxldized cil or iat is separated irom the' resulting mixture, preferably by means oi a high-speed centrifuge. Such peroxidiredoil or iat has beenicund to be highly useful in the al i dough in that it serves both as a shog agent and as a bleaching agent for the dough,l as disclosed in to substances formed as a result of some chemical 1 reaction.

The object of the present invention is to provide means for eectively improving an oil or fat and for treating oils andfats by subjecting the oils or rats to a preliminary modifying treatment.

inasmuch as this invention 'relates to apparatus for carrying out certain treatments for oils and fats, there will iirst be vdiscussed the problem from a. process standpoint, and thereafter the appa.

' No..i,994,992, to L. W. Haas and H. 0. Renner,` and in application Serial No. 245,502, led December 13, V1938,` (now Patent 2,316,62'1` dated April 13, 1943)..

The processes described in the above applica--` tion Serial No. 127,308'andPatent No. 1,994,992

are-for the purpose of-preparing oxidized oils or ratssuitable for use in baking Processes primarily for bleaching purposes. For instance, in the oxidation processes, an animal or vegetable oil or Patent No. l,994i,992 to L. W. Haas land H. O. Renner. y

-The above enzyme oxidized oil or fat may be refined to a certain extent by means of a process described and claimed in said application Serial No. 245,502. The latter application discloses a process in which oils cr fats, and especially peroxidized oils or fats havingr a rancid odor or flavor. or producing undesirable odors or avors in baked goods for instance are mixed with Water and plasmolyzed yeastor enzymes 'obtained from living microorganisms byy plasmolysis, autolysis, maceration, or suitable-mechanical means. The mix 'is constantly and thoroughly agitated, while avoiding aeration, ior 'a relatively short period of time and at a. temperature of about 20 to 50 C. The mix may then be kept for a certain period in an atmosphere of inert gas such as carbon dioxide,l if desired. The refined oil is isolated from the mix by centrifuglng at high speed. Y

It has nowl been found, as described inSerial No. 313,284, that by a special pre-treatment given theA oils or fats processed in accordance with the a highly improved product is obtained. The pretreatment lscarried out as follows, according to fat is agitated vigorously i'n the presence of enzyme extracts-and in the presence of air, oxygen, vor other gas containing free oxygen at a temperature between 32 and 140 F.,or prefer- -ably to 78 F. for a period depending` on the the teaching in Serial No. 313,284:

, A fatty acid \composition,.such as an mixtures thereof, preferably refined in accord- 4ance* with the ordinary well-known commercial to cause an oil to turn rancid or to impart to.

baked goods an unpleasantl flavor.

i `The, fatty materiel under treatment is'not intended to be subjected to an extended halogeniza tion. The glycerldes of a. fat or oil 'for instance should notbe halogenized. 'The amount of halogen used in a` glvenquantlty of fatty materielle l l ediblevegetable or animal `oil or fat, a fatty acid, or

preferably just enough to halogenize lthe substances causing rancidincation and/or other objectionable organoleptic changes. A slight excess of halogen above that needed to modify such substances wlll not detrimentally affect the final product in which the fatty material is used.

The proportions of halogen to fatty material to be treated cannot be definitely expressed since they may vary considerably depending upon the particular halogen employed, the medium in which it is employed, the'properties of the fatty material and the use to which the treated'fatty material is to be put. Since the aforesaid minor constituents are generally present in `an oil or fat in extremely small concentrations, proportionately small amounts of halogens are required to modify these constituents. From a practical standpoint it is impossible to carry on the present halogen treatment without employing some excess halogen. The halogen reacts first on the minor constituents and any excess will react with i 55 and 80 F. have been found more suitable' from an economical standpoint, since at such temperatures no cooling or heating of the fattyv material is necessary. Higher temperatures as, for instance, from 110 to 120 F., as a rule tend namely, hydrochloric acid, must be neutralized- -quent enzyme-oxidation.

without producing any color. Thus the optimum proportions of iodine incorporated in an oil may be determined by gradually adding iodine while no change in color of the oil is noticeable. As little as 0.001 per cent of iodine based on the weight of an oil has been found sufilcient -to modify such oil in the desired manner. In largescale manufacturing, approximatelyQ grams of iodine is found tobe suicient for the treatment of 1 ton of oil. The iodine is preferably used in solution. As high as 18 grams of iodine per ton of peanut oil may be used. The iodine solution .may be relatively dilute as, for instance, a concentration of about 0.3 per cent.

Bromine behaves more nearly like chlorine than iodine in the present process. It may be used as such in very minute quantities. Proportions of about 0.01 per cent based on the weight of an oil may be employed.

Halogenization with chlorine 'in the absence of w-ater in the present process makes unnecessary any treatment of a fatty material before subse- Chlorination 'in the presence of water requires an intermediate treatment. In other Words, the acid that is formed,

and the oil clarified.

In the case of'iodation, no intermediate treatment is required whether or not water is present to affect the stability of oils unfavorably and should therefore be preferably avoided. At such higher temperatures, the halogenization reaction per se does not differ noticeably from the reaction at ordinary temperatures so far -as the quality and properties of the treated fatty material is p concerned.

If the viscosity of an oil to be ltreated permits,

' lower temperatures are preferably used since they favor the desired reaction\of the halogens x with the minorconstituents to be modified The velocity of the reaction ybetween the glycerides of an oil and a halogen appears to decrease with decreasing temperatures, at a faster rate than the velocityof the reaction between .suchhalogen fand the more highly reactive minor constituents of the oil. 'Ihe result appears to be that at lower temperatures the desired reaction is more selec- By way` of illustration, the treatment of fatty material with each of the halogens in accordance with a preferred procedure will be set forth more vspecifically below.

At the preferred temperatures mentioned above,

` a refined peanut oil or cottonseed foil, preferably water-free, is Vthoroughly mixed with about 0.05

Iodine is the least reactive ofthe halogens with the glycerides, and in contrast to chlorine and bromine, it may be dissolved in edible oils up to relatively high .concentrations without becoming chemically united with the glycerides. The fact that excess iodine tends to produce a reddish or pinkish color renders'the use of iodine practical from the standpoint of ydetermining the'proportion'of iodine, neededto modify the undesirable minorconstituents. The iodine reacts substanduring the iodation. Bromine behaves somewhat similarly vto chlorine. In the absence of water no acid is formed, while inthe presence of water, hydrobromic acid is formed. The acid formed is neutralized and the neutralized material may be removed by high-speed centrifuging. Y

In application Serial No. 260,862,-i1led March 9, 1939, of which the present application is a continuation in part, a process of treating fatty material is set `forth in which fatty material, such as edible oils and fats, is mixed with chlorinated lime and then with'sulphuric acid to generate a small .amount of chlorine in the'body of the material to modify the small amounts of minor relatively unstable constituents therein. In this instance, as soon as the active chlorine freed from -the chlorinated lime by the addtiion of acid is itially free halogen element into fatty materialto obtain the desired effect. Apparatus of the present invention that has been found particularly efcient for use in the treatment of liquid ltially 'instantaneously with vsuch. constituents 75 online3-3ofFig.2;

Fig. 4 is a section view of the` reaction tube online 4-4 of Fig. 2 showing s. plan of lan agitator element-employed 4in the tube; Fig. 51s a vertical section of a gas regulator reaction tube employedfin the apparatus shown in Fig. 1;

Fig. 3 is a sectional view of the reaction tube means employed in plate Q and Il. i

The agitator means "-l I- comprises a plate havassasve Figs. 6 and 'l are fragments partly in section of pgrts of the gas regulator shown in Figs. 1 and Fig. 8 isa front view of a fragment of thel gas regulator shown 4in Fig. 1;

Fig. 9 is a side elevation partly in section of a modification of apparatus shown in Fig. 1; and

Fig. 10 is a ow sheet indicating the diner-ent materials treated and the different stages of treatment.

il preferred form of herein-described halogen treatment, particularly with chlorine gas, comprises a reaction tube l (Fig. 41), through which oil to be treated `is continuously passed at a 'predetermined Arate while agitating in the presence of chlorine, preferably undiluted and pure, fed into the body of the oil at a predetermined rate. tube is U-shaped and is mounted in a vertical position. Thevtube may be constructed of cast iron lined withrglass. One leg of the tube is provided with means for introducing chlorine. The other leg serves as an overow which provides for a constant head of oil in the tube. vflihe'oil level is shown at l inthe inlet leg of the rea@ tion tube. l

The oil to be treated may befed into the inlet legof the reaction tube l from anoil reservoir (not shown). The oil is ted into the reaction tube at a uniform, predetermined rate by means of a pump l. If desired, the rate of flow may be controlled by a. valve d as well as by the pump t.

When conditions are maintained uniform at allv times as. for instance, when the same oil with uniform characteristics vis treated under uniform conditions, ythe rate of feed of the oil may be fined by the size of` the impeller blade oi the the apparatus for thev The reaction 'of oonars is onu is attached to tno sooft above and below each of the'agitators il, respectively. by means of set screws and 2l. The discs Ii" are adjustable and the distances between them may be varied. In the drawingsthey are shown speed. The desired union of the chlorine gas and the oil is accomplished by a rotationof approximately 3,000 R. P. H. Sincelthe eilectiveness'of the chlorination treatment for the purpose described depends largely on the velocity with which intimate contact of the minor constituents of the oil with the reactive chlorine gas .can be established and upon the carrying out of the reaction to a satisfactory point, the agitator serves as an important element of the apparatus. The agitator shown dispersos the gas entering the reaction tube in'a hnely. divided condition and within the shortest possible time sro that it is practically instantssineouslyv completely absorbed by the oil. The deecting rods itl co-act edectively with the agitator elements ll todistribute the gas in the oil.

pump as well as by a control disc having a bore hole of nxed diameter, which is inserted in the leed pipe 't leading from the pump t to the reaction tube Il.' The said discA is indicated by the numeral d in the oil feed line b.

The oil leed line b passes into the inlet leg of the reaction tube l through a side arm "l adjacent the top of the said inlet leg and abovethe level at which the oil column is maintained. At the inner end of the oil feed line E is a elbow 8 placed in a position for directing the oil downwardly and in the direction in which the oil is rotated by. on agitator to be described below.4

The agitator is suspended from a cover' plate` 5 at the top of the inlet leg of the reaction tube l. The agitator comprises a rotary shaft l0. a

.The chlorine gas is led into the inlet leg of the readtion tube at a predetermined level below the level lof the oil through a pipe it. The pipe it passes through a cover plate 2l amxed tothe end of a side arm 20 of the reaction tube l. The openend of the pipe ttlis positioned preferably lsoas to admit the gas into the body of the oil at a point between two agitator elements ll.

'li'he'rateof introduction of the chlorine gas maybe controlled by a valve it inthe pipe lb which leads to a pipe dbprovided with a valve. di, which-,in turn is connected to the chlorine gas supply. The pipe db also leads to a pipe 32 provided with a valve 0l which in turn is connected to an inert gas supply. The purpose -of the inert gas is to replace chlorine in the pipe lines when found necessary. i The inert gas may be nitrogen.

In order to provide for effectively regulating the rate of introduction of chlorine gas into the reaction tube, a gauge unit shown in Figs.1, 5, 6,-

and 7 is connected to the pipe 26- by means of a pipe 34. The pipe 3l passes downwardly and is connected to a glass 'tube 34' which extends into a gauge-tube 35 to a point slightly above the bottom thereof and below the level of a gauge plurality of agitatordiscs II, and a plurality v ol deflecting rods l2.

The denectingrods I2 arev heldin place by` means o! suitable connections withlthe cover are mounted in statlonaryrposltlon about the agitator-s Il, parallel'to the shaft Il.

. The deflecting rods are spaced from the shaftsto permit rotation of the agitators Il. A plurality of means I3 are secured to the deilectlng rods for supporting a bearing il (Fig. 2) for the shaft l0. One such bearing-supportingmeans I3 is shown near the lower end. of the shaft Il and another adjacent the level of the oil in the reaction tube. The bearing-submitting means I3 are adjustable and are heid in place by set screws :l5 '(Fig. 3) co-acting with thedeecting rods I2l and bya set screw Il co-acting with the shaft in g perforations l1 (Fig. 4). Five such agitator 'and is connected to a pipe 40.

liquid 36, such as water. The glasstube Il' has its lower end 31 open to permit free passage of liquid or gas therethrough. 'I'he gauge tube 35 is. provided with a suitable gas-tight cover 30. vA passage 39 leading from the interior oi' the gauge tube 35 is provided in the cover 38 To the outside of the gauge tube 35 is attached a gauge stick Il provided with suitable markings to indicato liquid ievels moho gauge tubeanoto' indicate 4distances from the top end 4I of the said gauge stick 4|. The gauge Stick 4I is at'- tached atits upper end to a collar I2 which engages the gauge tube 35. The gauge stick is held in pface by means of a bolt 44 and-a nut The bolt 4I passes through an enlarged l5. openingi in the gauge stick 4I so that the latter may be adjusted vertically. The lower end of the gauge stiel:vr Il is free and permits the y movement of av slide valong the same.

:It is seen that byadniittlng gas into the reaction tube l under a given head ofoil, a oer-- tain pressure is needed to overcome this head. At the same time the rate of feed of the gas must be properly adjusted in accordance with the rate of passage of oil through the reaction tube so that the gas and oil are properly proportioned.

By adjusting the feed of gas so as to maintain the position of the meniscus of the gauge liquid great, the gauge liquid is forced out of the tube 34' and the gas eventually escapes through the passage 39.

To set the gauge, the top end 4I of the gauge stick 4i is positioned so that during the operation of the apparatus the meniscus of the gauge liquid in the gauge tube35 is maintained in horizontal alignment with the top end 4i of the gas passes into the tubey34' and forces the gauge liquid downwardly therein. When the movement of the gauge liquid in the tube 34 indicates that some pressure has been created, the valve 29 `is immediately opened. The valve 3l in the chlorine feed line. 30 is then adjusted until the desired operating pressure hasI been attained as will be observed by the lowering of the meniscus of the gauge liquid in the tube 34 to the readingindi-` cated by the slide 43. pressure is attained, the oil pump is immediately started and the feed of oil maintained at the desired predetermined rate of flow. 'Ihe feed of gas and oil is so proportioned that about 1 part by weight of chlorine per second is introduced into the reaction tube for every 1,000 parts by weight of oil passingA through the reaction tube in the same period of time; As indicated aboye, this proportion may be varied as found necessary.

From time totime by way of precaution, the

oil passing out of the reaction tube may be tested for its acidity. If the oil andthe chlorine gas are free from moisture upon entering the reaction tube, such acidity is not likely to develop gauge stick and of the slidable collar 42. Also.

during operation the meniscus of the gauge liquid in the tube 34 is kept in horizontal alignment with the top edge of the gauge slide 43. 'll'he distance between the tvv-o` meniscuses is' the equivalent of the head of oil in the reaction tube plus the added pressure required to feed the gas at the desired rate and in proper proportion to the oil. vBy. proper calibration, this distance may be predetermined. During the feed of the gas,

the gauge is observed from time to time to make certain that the proper rate of delivery is maintained.. If found necessary, the pressure of the gas is adjustedby 'manipulating the valve 3| in the gas fee'd line 30. y

For the purpose of preventing the escape of chlorine gas intothe atmosphere, it has been found advantageous to 'connect the pipe 40 to anabsorber. The absorber comprises a closed tank 4l. The pipe 40 is connected to a pipe 48 which extends downwardly through the center of the'tank 41 and is provided with an open provided in the bottom of the tank 41 in which is placed an overow pipe 52 which prevents clogging of the drainage hole by solid crystals -that are apt to form during the reaction of vthe chlorine with the absorbent. During the operation of the apparatus, the drainage'hole vis kept closed by means of a ping 53. AnyH gas which accidentally or ,otherwise passes through the gauge 35 Ainto the tank 41 is absorbed by the sodium carbonate without induencing 'the read--4 .ings on the gauge. j

In the operation ofthe-above apparatus, the reaction tube l is rst lled with the oil tofbe .treated'by pumping the oil-into thetube by means of the pump 3. When the levelof the oil reaches the level of the overflow pipe, namely? the level 2, the pump is stopped. The agitator' motor 2l is then startedlv The valve Il in the'- chlorinefeed line II is gradually opened, valve u' being momentarily kept closed. The ehlbnne and therefore routine tests are not required.

When stopping the operation of the apparatus, the oil pump is stopped and the valve 4 closed; the valve 3| in the pipe 30 is closed to shut ci! the 'supply of chlorine; the valve 33 in the pipe 32 is slowly opened, whereupon the inert gas passes throughthe pipe 26 into the reaction tube I and the feeding thereof is continued until all the chlorine in the various pipe connections has been replaced by inert gas. The valves 31 and .29 are-closed and the agitator is stopped. The oil in the reaction tube I may be drainedout by removing a drainage plug 55.

In Fig. 9 the means areshown ywhereby oil, may be treated with lodin solution in the proportions indicated above. e same type of reactiontube as ,that shown in Fig. 1 may be used and .thegas inlet arm 28r may be. s'ealed oi! by means of a plug 56. The iodine solution is fed into the top ofthe oil column in the reaction tube i from a container'l which may be made of glass and may be graduated as at 59. T 'he top section ofthe inlet leg of the reaction tube i is provided with two inlet arms 60 and 8l; the inlet arm 60 being `provided for the introduction 0f' the oil to be treated. and the inlet arm Il` being provided for the introduction of the iodine solution. The oil is fed into the reaction tube through the pipe 5 and the'elbow il in vthemanner described in connection with the apparatus shown in Fig. 1. The container 58 is, connected to the reactiontube by means of a'Iplpe i2 provided with a control valve 63. The open end oi the' pipe 62 withinthe reaction tube is sopladod that the iodine solution is delivered directly into the stream of oil entering the said reaction tube. The feed of the oil and of the iodine solution .il so controlled that .the iodine and the oilA arev properly proportioned. The'proper proportion, of iodine to oil may be roughly indicated by the r:olor of the treated oil leaving reaction tube. Il' the treated oil has a very faint pinkish shader the proportions maybe proper.l

i. Using the apparatus illustrated, a complete process for the preparation of a.highly -improved product for use as a shortening and bleaching agent -in the baking of dough, for instance, comprises the following steps as shown in the'ow sheet shown in Fig. l0: l i

1. 'The oil is pre-treated with'a' halogen and.v azitatedachishspeeatheoummhnou As soon as the desired being fed into a reaction zone 05 in proper proportions. Ii the resulting mixture containscacid,

.it is treated to neutralize the acid or remove the same. If the resulting mixture shows no acidity,

the acid-removal treatmentmay be ley-passed tion of the fatty material as at l.

3. The Aenzyme-oxidized fattyI naterial and active enzymes present in living micro-organisms at substantially room temperature onbelow about y 50 C. or preferably at 20 to 50 C. are mixed together as at 50.4 i

i. The fatty material is separated from the enzyme material and the resulting fatty product` maybe used as such for bleaching of dough.

5. Ylifv the oil resulting after theftreatment by means of the above steps is liquid atv room temperature, a lard-like product maybe obtained by mixing with the processed oil a hardened oil such as, for instance, hardened ground nut oil.

More speclcally, after the above speciilc pretreatment, 5000 parts by weight of a peanut oil is oxidized at 20 C. in the presence' of about 1000 parts by weight ci concentrated soy flour extract (obtained by mixing about 200 parts by Weight ci enzyme-active or unheat-treated soy ilour in about 1200 parts by Weight ci 0.2 per cent calciumy vchloride solution in water and centrifuging) diluted with about 5000 parts ci Water.

To the thus catalytically oxidized oil contained.

in the above mixture, about parts by weight of plasmolyced yeast are added, and these mixed together at 2d il. for about one and onenhali hours.

llloe pl-l during thlsenzyme refining process is maintained at about 6.5 to '7.0. The refined oil is separated from the resulting mixture by centrliuging, 'and may be blended with other oils or iets for use in baiting or other` processes.

ln the process described in Serial No. 313,204 as conducted in the apparatus of the present lnvenm tion, a pretreatment is applied to iatty acids or and oils, or mixtures thereof, for the nur! pose oi destroying or modiiyingcertain minor constituents thereof which are apt togive rise to undesirable odors and davor-s in theseA fatty Iinaterlals or more particularly to odors and flavors considered undesirable in the products in which;

paratus illustrated and claimedoherein affords particularly efficient means for conducting the said process as well as providing useful equipI ment for other mixing operations.

The use of a U-shaped reaction tube provides the apparatus is to be addedto present equipnient.' Such buildings frequently have ceilings so would probably requirev a hole between floors` through which the tube could extend. Both of these features would tend to limit the mobility of the apparatus.

A still further advantage in the use of the U- shaped type of tube is that it permits the location of the apparatus close to the edge of the usual processing tanks wherever desired, so that the overow from thou-member thus permits feeding the treated oil directly over the high sides. commonly about three feet above the floor, of the processing tanks and into the latter without the use of an additional pump. Il pump at that location would otherwise be `necessary to elevate the oil from the lower end oi a vertical type straight tube.

It will be clear from the foregoing that as a further advantage of the U-shape type unit, the overovv contributes as Aan important safety func-1l tion positive avoidance of any chance of poisonous gas, such as chlorine? escaping into the sur-v rounding atmosphere. This is in contrast to the probabilities in the operation of a straight tube, which, in continuous operation, always endange'rs the workmen because the control ci the liquid level in the reaction tube would reduire maintenance in performed manually with the nid ci an additional l valve by frequent careiul watching ci the liquid level. This is an important feature because a very slight difference in the quantity ci oil positively delivered by the pump into the'reactiontube and the quantlty'oi oil permitted to pass such additional valve is sumcient in continuous operation to cause a 'drop in the liquid level below the sas inlet as result of which the desired reaction would be prevented and the gas would bass to the at biosphere. ln contrast to auch ad arrangement, the liquid level is automatically maintained` by the overcvv.

t will iiuther be understood from the foregoing that in contrast to possible operation with a straight tube, the present invention assures the maintenance within the reaction tube of a constant `liduid level which` is important for uniform operation, that is, delivery of a xed amount ci reactive gas within the unit of time, also the raticoi outlet capacity oi' overovv and minimum to maximum capacity of pump feeding voil to the reacticn'tube being selected so as to permit sub stantial increase in the delivery of oil by the pump Without any other adjustment except that of the gas controlled gauge. The U-shape oi' the reaction tube and the overilovv 'from one arm f of the U-tube provide a positive means of keeping the opening of the gas feeding tube constantly immersed in oil, thereby providing an additional` safety factor.

The invention has been disclosed herein for ili lustrative purposes in its preferred embodiment, but4 it is to be understoodthat the scope of the invention is defined by the appended claims rather than by the foregoing description.

Iclaim:

1. Apparatus comprising a ils-shaped continuous passage of liquid therethroughand with the parallel arms thereof extending up- Wardly,v means for introducing liquid into a lrst tube for into said rst arm -at a lower level therein, the' other of said arms having an outlet opening in ythe upper portion thereof for the discharge of treated liquid, and a rotary agitator in said first arm removably suspended from the top thereof and having a plurality of disc-like elements, each extending in its respective single plane well across the crossv sectional area of said rst arm and capable of effecting agitation without propelling the material being treated lengthwise of said arm.

2. Apparatus comprising a U-shaped tube for continuous passage of liquid therethrough and with the parallel arms thereof extending upwardly. means for introducing 4liquid into a first arm ofsaid tube, means for introducing a gaseous treating reagent into said rst arm at a point below the upper level of the liquid, the other of said arms having an outlet opening in the upper portion thereof 'for the discharge thereof of treated liquid, and said outlet opening serving to determine the level of liquid in both of said arms, a high speed emixing means positioned in said ,first arm for mixing the gaseous reagent and liquid and bringing' about complete absorption of gas inthe liquid, said mixing meansl being capable of effecting agitation without propelling the material being treated lengthwise of said rst arm.

3.'In apparatus for mixing a treating reagent with a liquid to be treated, a treatment chamber,

the upper end of which is sealed against the escape of gases an agitator adapted to be sus. pended .in the liquid and comprising a rotatable liquid leading from a lower point of said chamber, and means leading into the lower part of said chamber whereby gas is introduced.

4. In apparatus for mixing a treating reagent with a liquid to be treated, a treatment chamber,

the upper end of which is sealed against the escape of gases an agitator adapted to be suspended in the liquid and comprising a rotatable shaft, a plurality of agitatorg secured to the shaft and spaced apart thereon, a plurality of deflecting rods mounted in stationary position about the agitators, parallel to the shaft and spaced therefrom to permit rotation of the said agitators, means secured to the said defiecting rods for supporting a bearing for the said shaft, an inlet for liquid to be treated at the upper portion of said chamber, an outlet for treated liquid leading from a lower point of said chamber, and means leading into the lower part of said chamber whereby gas is introduced.

5. Apparatus comprising a U-shaped tube for extending in its respective single plane well across the cross sectional area of said first arm and capable-of effecting agitation without propelling the material being treated lengthwise of said arm. the upperend of said first arm being closed against the discharge of any material and the upper end of the second arm of said U-shaped tubebeing closed except for said outlet opening for treated liquid.

HERBERT OTI'O RENNER. 

